I've looked through the 30 year plan for Greater Adelaide, but can't find anything showing what happens after the N-S Corridor is in it's entirety completed.
So what happens after the north south motorway is finished? Maybe this isn't worth it's own thread..but I've been thinking about what's going to be done next for a little while now..

Will there be work done to create a proper city ring route, as other cities around the world have?
Will there be work done to link NSM to the SE Freeway?
Will work be done to extend the NS corridor down to Victor Harbor/Port Elliot/Goolwa?

What are we likely to see? Perhaps nothing for quite some time after the state election?

Extending the SE Freeway down Glen Osmond Road, and turning Greenhill road into a motorway linking it to the NS motorway?
Perhaps tunnelling from Portrush Road, branching off and coming up in the parklands near Robe Tce, main tunnel continuing north in the empty land near the Womens prison on Grand Junction road, before continuing with a surface motorway north west between Yatala and Walkley Heights, through Cavan and linking up to Salisbury Highway?
Or continuing the NEXY to Nurioopta and beyond to the Riverland as a motorway?
Or upgrading the route to Port Wakefield/Port Pirie/Port Augusta?

If we look at NSW, Woolongong, Central Coast and Newcastle are linked to the capital by motorways, most of the way if not all the way.
Victoria is the same, with Geelong, Ballarat, Mornington Peninsula, Shepparton and almost Bendigo all the way on motorways.
Same deal in Qld, with Gold Coast, Sunshine Coast, Coolangatta linked to Brisbane via motorway.

Or perhaps rather then building more motorways, the next step should be to improve existing major arterial roads? You drive down some roads, and it's start stop start stop at way too many sets of traffic lights.

There's a bit of momentum at the moment, which I think should be maintained with more projects.

The 30 year plan is more about land use planning, and where houses should be built. It has a small component related to infrastructure, but there is an infrastructure and land use plan out called the ITLUP, as well as the Infrastructure Plan that is due to be revised soon.

Given the focus on infill, I doubt there will be a big focus on roads, but rather on improving active transport and public transport in the inner suburbs, such as trams, to support ongoing infill. Our low population growth also reduces the need for big road building projects for commuters, but hopefully a freight link between the South Eastern Freeway and the North-South Motorway will be considered.

GoodSmackUp wrote:With Virginia and Two Wells both expanding I reckon they might jump in soon and upgrade Port Wakefield Road to Freeway grade

Port Wakefield Road from Virginia to CBD will not be upgraded to freeway, Northern Connector/North-south Motorway is the freeway from there to CBD.
The building of the Northern Connector is because Port Wakefield Road from Virginia to CBD is not going to be a freeway.

GoodSmackUp wrote:With Virginia and Two Wells both expanding I reckon they might jump in soon and upgrade Port Wakefield Road to Freeway grade

Port Wakefield Road from Virginia to CBD will not be upgraded to freeway, Northern Connector/North-south Motorway is the freeway from there to CBD.
The building of the Northern Connector is because Port Wakefield Road from Virginia to CBD is not going to be a freeway.

I believe GoodSmackUp is possibly talking about Port Wakefield road between Virginia(just to the north of the start of NEXY/end of Northern Connector) and Two Wells.

GoodSmackUp wrote:With Virginia and Two Wells both expanding I reckon they might jump in soon and upgrade Port Wakefield Road to Freeway grade

Port Wakefield Road from Virginia to CBD will not be upgraded to freeway, Northern Connector/North-south Motorway is the freeway from there to CBD.
The building of the Northern Connector is because Port Wakefield Road from Virginia to CBD is not going to be a freeway.

I believe GoodSmackUp is possibly talking about Port Wakefield road between Virginia(just to the north of the start of NEXY/end of Northern Connector) and Two Wells.

Swanport Bridge has been in the news for the wrong reason a few times lately. I don't know what it would cost to duplicate that as a project to remove a safety bottleneck - one lane each way and a narrow footpath one side (no bike lane/path), joining dual carriageway freeway from Glen Osmond to dual carriageway to beyond Tailem Bend. It is on the route to the new The Bend Motorsport Park and Melbourne. Victoria is gradually extending the dual carriageway Western Freeway towards the border, we should be looking at doing our part towards a full dual carriageway link between Adelaide and Melbourne. Whether we like it or not, there are a lot of trucks and cars on that road. I drove that way over the weekend, and the bridge feels much more constricted than the Dukes Highway further out.

Extend the dual carriageway Sturt Highway from Nuriootpa to go around Truro and down to the Murray flats.

Announce funding to create a detailed ten-year plan to solve heavy transport that currently uses Portrush/Hampstead/Grand Junction Roads. Options could include the east-of-the-hills bypass that links to the Sturt Highway Truro Bypass, a "North South Corridor"-type solution on roughly the current alignment, or on Cross Road alignment, or completely different. I'd imagine that there is several years worth of consultation and planning needed to make the plan, then start building it from around 2024 when the N-S corridor should be completing.

There is also a good range of intersections and level crossings in the metro area, plus finishing the railway electrification, to keep the large crumbs falling off the table as well.